The International Phonetic Alphabet (IPA) requires specific names for the symbols and diacritics used in the alphabet. It is often desirable to distinguish an IPA symbol from the sound it is intended to represent, since there is not a one-to-one correspondence between symbol and sound in broad transcription. The symbol's names and phonetic descriptions are described in the Handbook of the International Phonetic Association. The symbols also have nonce names in the Unicode standard. In some cases, the Unicode names and the IPA names do not agree. For example, IPA calls "epsilon", but Unicode calls it "small letter open E". Letters The traditional names of the Latin and Greek letters are used for unmodified symbols. In Unicode, some of the symbols of Greek origin have Latin forms for use in IPA; the others use the symbols from the Greek section. Examples: Note The IPA standard includes some small capital letters, such as , although it is common to refer to these symbols as simply "capital" or "cap" letters, because the IPA standard does not include any full-size capital letters. Cursive-based letters A few letters have the forms of cursive or script letters. Examples: Note Ligatures Ligatures are called precisely that, although Unicode often mistakenly calls them "digraphs" and some have dedicated names, such as ash and ethel. Examples: Rotated letters Many letters are turned, or rotated 180 degrees. Examples: Notes A few letters are reversed (flipped on a vertical axis): Notes One letter is inverted (flipped on a horizontal axis): inverted capital small R. ( could also be called an inverted w, but turned w is more common.) Letters with extra lines, curls and serifs When a horizontal stroke is added, it is called a crossbar: barred h, barred o, reversed barred glottal stop or barred ayin, barred dotless j or barred gelded j (apparently never 'turned f'), double-barred pipe, etc. One letter instead has a slash through it: slashed o. The implosives have hook tops: hook-top b, as does hook-top h. Such an extension at the bottom of a letter is called a tail. It may be specified as left or right depending on which direction it turns: right-tail n, right-tail turned r, left-tail n, tail z (or just retroflex z), etc. But note: eng or engma, meng, heng. When the tail loops over itself, it's called curly: curly-tail j, curly-tail c. There are also a few unique modifications: